Asthma is a condition of the airways. When an individual is exposed to something (e.g. cat hair or cold or exercise) the small airways muscle walls contract. This narrowing causes the characteristic wheeze as air struggles to get out of the lungs. Some air will be trapped in the alveoli and bronchioles, the smallest parts of the lungs where gases are exchanged. Inhalers such as Salbutamol (Ventolin) help open up these airways and release this trapped air. Steroid inhalers used over 4-6 weeks will prevent this narrowing occurring in the first place when a trigger is encountered.
Can I dive with asthma?
This is not always a straightforward answer. If an individual were to trap air as described above when they are diving then, as they ascend, this air will expand and can burst a lung.
If you have exercise or cold induced asthma or wheeze then diving is not advisable. Diving requires you to exert yourself breathing cold air. Even when diving in hot climates the air in the tanks is often cold and diving is more hard work on your body than you may realise.
If you have allergy induced asthma then diving may be possible depending on your level of control.
It is a condition you will always need to discuss with a doctor.
What does the doctor need to know?
These are the key questions we would wants answers to when you contact us to help us decide about whether you are safe to dive.
- When was the last time you were on asthma medication?
- What asthma medication were you on?
- Have you ever been hospitalised because of your asthma?
- Have you ever been in intensive care for your asthma?
- Have you ever required oral steroids for your asthma?
- Do you dive already? If so, how many dives and have there been any problems?
- Do you have any other chest problems?
- Do you undertake regular cardiovascular exercise (where you raise your heart rate) and if so, does your chest ever feel tight or do you get any wheezing (whistling noises)? In particular, do you have any trouble when you exercise in cold environments? For example, going for a run on a cold day?
Are there any tests to check if I am safe?
We can do an asthma stress test. It is the closest we can get to simulating you going underwater and exerting yourself. Email firstname.lastname@example.org for more information.
This will be to see if your peak flow drops (a gross measure of lung volume).
If your lung volume does drop then this suggests that a part of the lungs are closing off and trapping air, as discussed in the ‘What is Asthma?’ section above
What do I need to do before an Asthma Stress Test?
For a stress test at our facility you will need to bring the following:
- Your current asthmatic medication
- Suitable clothing and footwear for cycling
Prior to the test, you should continue your preventative medication but should not use a salbutamol inhaler for 48 hours before the test if at all possible.
You should also avoid caffeine and chocolate. We also ask that you have something to eat before the stress test
If you are not able to do this please let us know well before hand with your reasons. The Doctor can then discuss the situation with you, as if you cannot stop your medication for 48 hrs you may not be able to undertake the test.
On arrival you will be required to sign a declaration to say you have fulfilled these criteria and consent to the test. There is a small risk that we could induce an asthma attack.
I have been told I can dive by my doctor. What do I need to do to keep safe whilst diving?
Asthma can deteriorate when you become unwell with a cough or cold or become exposed to new allergens. So, if you have any wheeze or increased shortness of breath then you should not dive and see a doctor.
As long as you are well and stable then simple peak flow measurements will give an indication of the control of your asthma. Your GP may have given you a meter to monitor this.
It is advisable to keep an eye on this number. You should know what your best is and do twice daily (morning and evening) peak flow readings during the diving season.
If your peak flow drops more than 10% from your best then you should not dive until this recovers to normal and you fell well.
For more information on this please refer to the British Thoracic Society guidelines on respiratory aspects of fitness for diving.